Microsomal 20 alpha-hydroxysteroid dehydrogenase activity for progesterone in human placenta.

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Fukuda T, Hirato K, Yanaihara T, Nakayama T

Microsomal 20 alpha-hydroxysteroid dehydrogenase activity for progesterone in human placenta.

Endocrinol Jpn. 1986 Jun;33(3):361-8.

PubMed ID
3463506 [ View in PubMed
]
Abstract

Placental 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) activity was studied in order to evaluate the mechanism of continuation of pregnancy and initiation of labor. The placentas obtained at various gestational weeks were homogenized and fractionated into "nuclear", "mitochondrial", "microsomal" and "supernatant" fractions. Each fraction was incubated with 14C-progesterone and a hydrogen donor. Enzymatic activity was measured by the conversion of progesterone to 20 alpha-dihydroprogesterone. The highest activity of 20 alpha-HSD for progesterone was found to be localized in "microsomal" fraction. The Km constant of 20 alpha-HSD was 4.5 X 10(-6)M for progesterone in "microsomal" fraction. It was found that placental microsomal 20 alpha-HSD required NADPH as well as NADH. 20 alpha-HSD activity for progesterone increased as gestational weeks advanced. The addition of DHA-sulfate and DHA inhibited 20 alpha-HSD activity for progesterone significantly, suggesting that the steroid produced by the feto-placental unit may be involved in the metabolism of progesterone in human placenta.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
NADHAldo-keto reductase family 1 member C1ProteinHumans
Unknown
Not AvailableDetails
NADHEstradiol 17-beta-dehydrogenase 1ProteinHumans
Unknown
Not AvailableDetails
NADHEstradiol 17-beta-dehydrogenase 2ProteinHumans
Unknown
Not AvailableDetails